Question

a) What is the purpose of a diffraction grating in a spectrophotometer?

to detect the amount of light that is absorbed by the sample to focus the light onto the cuvete

to separate the different wavelengths of light from the light source

to prevent fluctuations in light intensity

b) What is the purpose of a photomultiplier tube?

it detects the photons that were not absorbed by the sample

it selects a narrow range if photons

it is a source of photons

it contains the sample solution

Answer 1

1) b) the purpose of a diffraction grating in a spectrophotometer is to separate the different wavelengths of light from the light source.

For example, white light will be separated into its constituent wavelengths.

Instead, A spectrophotometer is an instrument that measures the amount of light absorbed by a sample.

2) b) selects a narrow range of photons.

A photomultiplier tube, useful for light detection of very weak signals, is a photoemissive device in which the absorption of a photon results in the emission of an electron.